聚丙烯层压纸绝缘电缆发展现状

本文综述了数十年来国内外聚丙烯层压纸（PPLP）在常温与低温条件下的介电、理化特性研究进展,介绍了PPLP绝缘高压电缆与PPLP绝缘高温超导电缆的应用现状,展望了PPLP材料与PPLP绝缘电缆未来的发展趋势。     

液氮环境中3种聚合物薄膜老化和拉伸状态下的绝缘强度

用于超导设备的薄膜型绝缘材料绕包于导体时往往承受一定的绕包张力,且由于工作环境温度的变化、机械应力等作用会发生老化.为研究薄膜型绝缘材料在液氮环境中老化拉伸状态下的绝缘强度,设计了一套测试电极系统对聚酰亚胺(Kapton)、聚丙烯层压纸(PPLP)和聚四氟乙烯(PTFE)3种薄膜在液氮中经过不同老化处理后拉伸状态下的工频和直流绝缘强度进行了实验研究,结果发现老化拉伸状态下交、直流击穿电场强度大多在较小幅度内发生变化,而经过冷热循环处理后的聚丙烯层压纸交流、直流击穿电场强度均发生了跳跃性地下降,因而在选择聚丙烯层压纸作为超导电力设备的绕包型绝缘材料时,应充分考虑工作温度剧烈变换导致的材料老化因素的影响.3种材料的直流击穿电场强度要普遍高于交流击穿电场强度.     

矿物绝缘电缆船舶应用若干问题的探讨

船用耐火电缆有三种类型,就可靠性而言,矿物绝缘电缆较之云母带绕包结构的电缆或挤包特殊的耐火复合层的电缆,可以列为优选。但在实船使用中矿物绝缘电缆会遇到诸如现场敷设、中间联接器、外径尺寸和重量等问题,应按船舶实际敷设环境工况,做出相应对策。     

3种聚合物薄膜拉伸状态下的绝缘强度研究

研究了聚四氟乙烯(PTFE)、聚酰亚胺薄膜(PI)、聚丙烯层压纸(PPLP)3种聚合物薄膜经液氮浸泡和冷热循环后在拉伸状态下的电气绝缘强度,并与未处理的样品进行对比。结果表明:未处理时,PI薄膜的工频绝缘强度最大;经液氮浸泡后,PTFE和PI薄膜的工频绝缘强度相当,而PPLP薄膜的工频绝缘强度相对稳定。     

电老化后聚丙烯层压纸的绝缘性能变化及局部放电特性

高温超导电缆所用的聚丙烯层压纸(PPLP)为绕包式结构,由于整流器件的存在使其承受交直流复合电压,在对接间隙处易发生局部放电.在长期工作电压下,其绝缘性能会发生变化,同时会对局部放电产生影响.本文在液氮环境下对PPLP进行直流电老化实验,采用内部放电模型来模拟对接间隙,并结合仿真计算分析内部放电模型的电场分布,对电老化机理和局部放电结果进行讨论分析.结果表明:电老化后PPLP的电导率和相对介电常数随老化时间的增加整体呈增大趋势,其直流电气强度随电老化时间的增加逐渐下降,但仍保持良好的绝缘性能.局部放电的剧烈程度随PPLP电老化时间的增加有所增大,局部放电发生的相位主要集中在复合电压的上升阶段,且复合电压中的交直流比例是影响局部放电的主要因素.     

绕包绝缘技术问题

简要分析了绕包绝缘技术的若干问题，介绍了绕包绝缘的绕制过程和产品试验结果，并提出降低绕包绝缘干式变压器局部放电量的措施。     

聚醚醚酮在核电厂矿物绝缘电缆保护层的应用

核电厂用矿物绝缘电缆由于长期在高温、振动、辐照等恶劣环境条件下运行,传统的交联聚乙烯护套在此环境下易发生老化、裂解、破碎,从而影响矿物绝缘电缆使用寿命和信号测量准确性。通过分析交联聚乙烯与聚醚醚酮材料的性能差异和几种典型加工工艺,选择将聚醚醚酮丝带绕包熔覆在不锈钢外壳作为矿物绝缘电缆保护层。     

275kV HPL纸绝缘充油电缆的研制

<正> 1.前言近年来随着城市电力需要量的增加,地下输电线路大容量化、高压化提到了日程,各方面都在进行超高压充油电缆低损耗绝缘材料的研制.从提高传输功率的角度,275和500kV级对介质损耗低、击穿强度高的新型绝缘材料的要求也日益强烈.在这种情况下发展了介电特性、绝缘强度优越的聚丙烯复合纸(PPLP纸).但是,复合纸具有径向油流阻力火的缺点.本文介绍了日本藤仓公司,为了克服这一缺点而研制的孔状塑料复合纸(HPL)和以HPL纸绝缘的275kVl×2000     

关于超高压电缆纸包绝缘发皱问题

本文主要论述500kV超高压电缆纸包绝缘发皱问题。文中分析了引起纸包绝缘发皱的原因,认为主要有三方面:1.纸包绝缘后予弯曲和收盘半径的影响;2.纸含水量的影响;3.包纸时各纸包头张力大小的影响。文中提出了解决方法。     

聚四氟乙烯绕包绝缘导线研究与应用

本文通过对聚四氟乙烯绕包绝缘导线的研究,详细介绍了聚四氟乙烯绕包绝缘导线导体、编织屏蔽层、绕包绝缘层在工程应用中需要重点关注的指标,为工程师提供了聚四氟乙烯绕包绝缘导线的应用和选型参考。     

聚丙烯簿膜木纤维复合纸在超高压电力电缆中的应用研究

本文在聚丙烯木纤维复合纸国内产品和日本产品比较的基础上对其性能作了实验性研究,应用常规方法和微观分析手段研究了复合纸与浸渍剂的电气性能和相容性,对实验结果进行了分析讨论,对实际生产提出了一些建设性意见.     

Long-term testing of a low-loss 800 kV PPLP insulated SCFF cable

This paper describes the dielectric and accelerated aging tests on an 800 kV AC polypropylene laminated paper (PPLP) insulated low-loss SCFF cable prototype. The test program was developed to validate the PPLP technology for future Hydro-Quebec 765 kV St-Lawrence under-river crossings. The paper reports on the cable and accessories characteristics, the test line construction, the test program, and the main results obtained. The successfully completed program has shown the overall very good performance of the cable and its accessories     

厦门220kV春围Ⅱ路海底电缆工程概述

厦门220 kV春围Ⅱ路海底电缆首次在国内使用了大截面(2 500 mm2)、高电压(220 kV)等级的自容式充油聚丙烯薄膜木纤维复合纸(PPLP)绝缘复合光纤电缆.介绍了该海底电缆的选型思路、电缆结构以及用于海底电缆敷设的自行设计的退扭系统,对海底电缆光纤测温、油压监测、海域视频监视等辅助系统进行了阐述.     

Development of 3‐in‐one high‐temperature superconducting cable

A three‐in‐one HTS cable has been developed. Its cable core is composed of a conductor and a shield wound with BSCCO and electrical insulation of the PPLP. The three cable cores are covered in thermal insulated stainless corrugated pipes. The BSCCO wires represent a dramatic innovation by virtue of a newly developed process named Controlled Over‐Pressure (CT‐OP). As a new cable technology, a 350‐m thermal insulation pipe was tested for 7 months to find that the life of the vacuum intensity is more than 10 years. The HTS cable with tension members was designed for installation into an underground duct. In addition, a fault current of 23 kA, 0.63 s, was applied to a sample cable with no damage to the BSCCO wires or the cable insulation. These technologies will be applied to the Albany project in the USA. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(1): 15–24, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20577     

Development of 500 kV DC PPLP-insulated oil-filled submarine cable

This paper outlines the development of a 500 kV DC oil-filled submarine cable capable of transmitting 2800 MW with ±500 kV 2800 A bipole system. Polypropylene laminated paper (PPLP) was employed as the insulation material, which is the world's first application to DC cables. The conductor size is 3000 mm², which is the largest size for submarine cables ever put into practical use. Through various fundamental and prototype tests, the cable proved to have excellent electrical characteristics for DC voltage as well as transient overvoltage. The cable and accessories are undergoing a long-term accelerated aging test as the final confirmation of their reliability and stability     

500-kV long-distance cable completed in Japan

The first 500-kV long-distance cable line is described. This oil filled self-contained cable has been installed along the Seto-Ohashi bridge connecting Shikoku, the fourth largest of the four major islands that constitute Japan with Honshu, the main island. The power flow will generally be from Shikoku where there is a surplus of power to Honshu, the main island. The technical features of the cable and its installation are described. Polypropylene laminated paper (PPLP), a low-loss insulation paper with high dielectric performance, was adopted, allowing the cable to carry the required transmission capacity of 1200 MW per circuit without forced cooling. The number of splices is also reduced by approximately 40%, resulting in further economy     

Development of 500 kV dc PPLP-insulated oil-filled submarine cable

This paper outlines the development of a 500 kV dc oil-filled submarine cable capable of transmitting 2800 MW with a ±500 kV 2800 A bipole system. Although polypropylene laminated paper (PPLP) has been employed as ac cable insulation material, this is the world's largest first application to dc cables. The conductor size is 3000 mm², which would be the largest size for submarine cables. Various fundamental and prototype tests have proved that the cable has excellent characteristics electrically as well as mechanically. The cable and accessories are currently undergoing a long-term accelerated aging test as a final confirmation of their reliability and stability. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120 (3): 29–41, 1997     

高温超导电缆及其低温绝缘研究现状

概述了世界上高温超导电缆的研究历史和现状,介绍了高温超导电缆本体的基本结构及绝缘要求,分析了高温超导电缆主绝缘的结构及存在的问题。针对高温超导电缆中使用的液氮和几种低温固体绝缘材料,分别介绍了其在低温环境下介电性能的相关研究进展。总结发现：液氮的击穿场强受到气泡和电极材料的影响;液氮下绝缘材料的直流击穿场强高于交流击穿场强;聚酰亚胺在液氮下的交直流击穿场强高于聚丙烯层压纸;低温会抑制环氧树脂中电树枝的生长。     

V-t characteristics of partial discharge inception in liquid nitrogen/ PPLP/sup /spl reg// composite insulation system for HTS cable

In this paper, we studied partial discharge (PD) inception characteristics and V-t characteristics of PD inception in liquid nitrogen (LN/sub 2/)/polypropylene laminated paper (PPLP/sup /spl reg//) composite insulation system for high temperature superconducting (HTS) cable. Experimental results revealed that the magnitude of initial PD was in the range of 2.0-30 pC irrespective of butt gap condition and the initial PD was generated at the first and third quadrant of voltage phase. PD inception electric field strength (PDIE) without butt gap was 5-10% higher than that with butt gap and thicker butt gap gave larger PDIE drop. Moreover, PDIE with butt gap depended on the butt gap thickness and the number of PPLP/sup /spl reg// layers. The reason is explained by the existing probability of weak points of electrical insulation at butt gap. Finally, lifetime indices n of V-t characteristics at PD inception were obtained as 80-100 irrespective of butt gap condition. These values showed enough flat characteristics of V-t phenomena of electrical insulation.     

Electrical insulation characteristics of cold dielectric high temperature superconducting cable

For the optimization of electrical insulation design for high temperature superconducting (HTS) cable, evaluation of electrical insulation characteristics especially for butt gap of LN/sub 2/ impregnated cold dielectric (CD) which consists of the wrapped tape insulation impregnated with LN/sub 2/ plays an important role. This paper presents partial discharge (PD) inception and breakdown characteristics in LN/sub 2/ impregnated butt gap model which modeled a weak point of the wrapped tape insulation impregnated with LN/sub 2/ and cable model with short length with polypropylene laminated paper (PPLP/sup /spl reg//), Nomex/sup /spl reg// paper and cellulose paper. PD current pulse was found to have a steep rise time of /spl sim/ ns and amplitude of /spl sim/ tens /spl mu/A at PD inception voltage region. Little dependency of breakdown stress on the insulating material is found. PD inception stress is almost independent of insulation thickness of 1 to 3 mm. The requirement insulation thickness for 66 kV class HTS cable is estimated to be /spl sim/ 5 mm under PD-free condition from viewpoint of long-term reliability.